1. Field of the Invention
The invention disclosed herein relates to a technique for measuring permeability of geologic formations.
2. Description of the Related Art
In exploration for hydrocarbons, it is important to make accurate measurements of properties of geologic formations. In particular, it is important to determine the various properties with a high degree of accuracy so that drilling resources are used efficiently.
Generally, oil and gas are accessed by drilling a borehole into the subsurface of the earth. The borehole also provides access for taking measurements of the geologic formations.
Well logging is a technique used to take measurements of the geologic formations from the boreholes. In one embodiment, a “logging tool” is lowered on the end of a wireline into the borehole. The logging instrument sends data via the wireline to the surface for recording. Output from the logging instrument comes in various forms and may be referred to as a “log.” Many types of measurements are made to obtain information about the geologic formations. One type of measurement involves determining permeability of a formation.
The permeability of a formation is important to know because the permeability is a measurement of an ability of the formation to transmit fluids such as hydrocarbons. One can use the permeability of a formation to determine an amount of hydrocarbons that can be recovered from the formation.
Therefore, what are needed are techniques for logging the permeability of geologic formations.